Lubricating composition



United States Patent 3,177,144 LUEREQATENG tCflll/ii fldi'iiflhl Thomas E. Reamer, El Cerrito, and Echo E. Weigel, Berkeley, (Iaiiii, assignors to Shell @il Company, New York, N.Y.,a corporation of Delaware No Drawing, Filed Earn. 23, 1%1, No. 83,947

6 Claim. (@l. 252-325) This invention relates to aqueous base, metal-working lubricating compositions. More particularly, it relates to extreme pressure water-base metal cutting fluids for use i in cutting, drilling, reaming, grinding and other machining and forming operations of ferrous and non-ferrous metals.

It is known that water-base cutting fluids possess good cooling properties, but that they lack the lubricating and extreme pressure properties of oil base lubricants. On the other hand, oil base lubricants are inferior coolants and cause odor, smoke, and staining.

The art discloses various water-base cutting fluids, most of which lack extreme pressure properties. Because of the multiplicity of additives which the majority of such fluids contain, they are unstable, tend toward phase separation and foaming, and are diflicult and expensive to prepare. Among the materials commonly used in such water solutions are 18.11 alkali, e.g., borax, sodium carbonate or trisodium phosphate, an anti-rust agent, e.g., sodium nitrite or triethanolamine, and wetting, buffering and solubilizing agents. The metal wetting additives may be water-soluble non-ionic compounds such as a reaction product of alkylphenol-ethylene oxide or a block polymer of ethylene oxide and propylene oxide sold commercially under the trade name of Plu-ronics (Wyandotte Chemical Company).

It is an object of this invention to provide a metal-working aqueous base lubricant having both good cooling and good lubricating properties. Another object of the invention is to provide a non-corrosive Water-base cutting fluid. Still another object of the invention is to provide a stable Water-base cutting fluid useful at high speeds, elevated temperatures, heavy loads and extreme pressures.

The above and other objects are attained by the present invention which provides a metal-Working lubricant of an aqueous base such as water to which is added a small amount (0.515%) of a new and novel compound, namely, a water-soluble (di)-alkali metal salt of chloro C alkyl phosphonic acid. Water base solutions of this type form excellent extreme pressure metal Working lubricants. Such solutions are particularly compatible with certain additives to produce a still more effective metal working lubricant. Such 'a formulation may comprise an aqueous base such as water to which is added from about 0.5% to about 15%, preferably from about 2% to about by weight each of (1) a water-soluble (di) alkali metal salt of chloro C 'alkyl phosphonic acid, (2) an alkanolamine salt of a C1240 saturated or unsaturated fatty acid, (3) a free alkanolamine and (4) a water-soluble heterocopolymeric alkylene glycol, ether or ester thereof, wherein the different oxyalkylene units are substantially randomly distributed throughout the entire polyoxyalkylene chain. The final water base fluid should have a pH between 8 and 11, preferably from about 9 to about 10. This is accomplished by addition of excess base (alkali hydroxide, e.g., NaOH) used in forming the phosphonate salts.

The combination of the above essential additives functions in a particular manner and produces an outstanding metal working fluid. The normal alkali metal chloro C alkyl phosphonate functions as an extreme pressure and load carrying agent. The alkanolamine carboxylate decreases bearing wear and grease loss. The free alkanolamine inhibits metal corrosion, particularly of ferrous metals, without producing any undesirable side effects,

lidihlid FIC . clud-e sodium, potassium and/ or lithium salts of said acid,

which acid portion of the salt can be represented by the general formula Where R is a C 4 alkyl radical, preferably a C alkyl radical such as methyl or ethyl radical and the chlorine atom (Cl) is in the alpha position relative to the phosphorous atom and A is an alkali metal anion as defined. Examples of such compounds include disodium chloromethyl phosphonate, disodium alpha-chloroethyl phosphonate, disodium alpha-chlorobutyl phosphonate, dipotassium chloromethyl phosphonate, dipotassium alphachloroethyl phosphonate, dipotassium alpha-chlorobutyl phosphonate, dipotassium alpha-chloroisop-ropyl phospho nate, dilithium chloromethyl phosphonate, dilithium alpha-chloromethyl phosphonate, dilithium alpha-chloropropyl phosphonate and mixtures thereof. A small excess of alkali hydroxide is used so that the pH of the Water solution is above 8.

The alkanolamines include mono, diand triethanolamine, isopropanolairnne, butanolamine, N,N-dimethylisopropanolamine and the like. These amines are also used to make the amine salts of C1240 fatty acids such as lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, ricinoleic acid and the like. Preferred amine salts are triethanolamine oleate, triethanol amine ricinoleate and mixtures thereof.

The water-miscible heterocopolymer polyalkylene oxide fluids enhance the cutting performance of the compositions of the persent invention by enhancing metal wetting. The above oxides are heterocopolymers of dissimilar alkylene oxides such as copolymer ethylene oxide and 1,2 propylene oxide [poiy(oxyethylene-1,2-oxypropylene)glycol], as well as monoethers and monoesters thereof, preferably at oxide ratios of from :25 to 10:90 ethylene oxide to LIZ-propylene oxide, and molecular weight of from about 250 to about 1500.

By a ratio of from 75 :25 to 10:90 is meant that, in the formation of copolymer the amount of 1,2-propylene oxide is from /3 to 9 times the amount of ethylene oxide present, by Weight, the pants or proportions of the 1,2- propylene oxide being given last. These materials are described in US. Patents 2,425,755 and 2,425,845. The copolymer diols may be employed in a modified form as the monoethers or monoesters of monohydric alcohols or monobasic acids with the diols. Both the alcohols and the monocarboxylic acids preferably have from 1 to about 5 carbon atoms.

Minor amounts (0.01-l%) of anti-foaming, masking, bactericidal and anti-corrosive agents for ferrous metals, copper and copper alloys, and/or, perfuming agents, may be added to improve the compositions of this invention. Among such materials may be included: anti-foaming agents, e.g., organic silicone compounds illustrated by dimethyl silicone polymer; phosphates, e.g., tributyl phosphate, alkali metal polyphosphates illustrated by sodium alkyl polypaosphates; masking agents, e.g., low molecular weight aldehydes (acetaldehyde); oil of pines, oil of mirbane; bactericides, e.g., alkyl phenols and phenates such as sodium o-phenyl phenate; and copper anti-cor rosion agents, e.g., mercaptobenzothiazoles (sodium mer-' captobenzothiazole), and the like.

The following compositions are representative of the invention, which can be used-neat or diluted with-from 1 to parts of water, as metal-working lubricants for cut-' ting, drilling and the like. The proportions are given in percentages by weight.

Composition A: Percent Dipotassium chloromethyl phosphonate 0 OK (ClCHzi 4.12 Oleic acid 0.05 Triethanolamine 3.00 Heterocopolymer of ethylene oxide -1,2-propy1- ene oxide (72/25) having a viscosity of 1400 at 100 F 2.00 Na o-phenylphenate 0.05 Na alkyl polyphosphate 0.02 Na mercaptobenzothiazole 0.50 Water Balance Composition B:

Dipotassium chloromethyl phosphonate 5 Triethanolamine oleate 0.1 Triethanolamine 1.5

Heterocopolymerof ethylene oxide-1,2-propylene oxide (72/25) having a viscosity of 1400 at 100 F. 3.0

Water Balance Composition C:

Disodium chloromethyl phosphonate 4 Triethanolamine oleate 0.1 Triethanolamine 1.5 Heterocopolymer of ethylene oxide-1,2-propylene oxide (72/25) having a viscosity of 1400 at 100 F. 3.0

Water Balance Composition D:

Disodium chloromethyl phosphonate 4 Triethanolamine ricinoleate 0.5 Triethanolamine 2 Heterocopolymer of ethylene oxide-1,2-propylene oxide (72/25) having a viscosity of (B) Test fluids were circulated over fresh steel turnings and time of rusting noted.

(3) Foam test: Test fluid stirredfor 1 minute in Waring Blendor and foam and liquidvolurne noted. 7

(4) Storage stability: Amount of phase separation noted of test fluids when. stored, over a'temperature range of 5 C. to room temperature.

(5) Machining tests: Thread test- 30 inches of /2-in..-13 pitch threadwere cut with high speed steel, tangent Chasers at 65 s.f.p.m., with difierent test fluids Surface conditions of thread and size of weld (pick-up) on chaser flank were noted and rated where 0=excellent threads and no pick-up and 100:poor threads and heavy pick-up.

Lathe tool friction test-In heavy duty lathe turning of AISL4340 alloy steel, the toolchip coefiicient of friction was equal to that of a premium quality petroleum cutting oil containing sulfur, chlorine Y and fatty additives.

rust test (B) were effective as rust inhibitors for over 13 days with no sign ofrusting of the steel turnings. Oh the other hand a commercial oil-in-water emulsion, cutting fluid (X) containing sodium sulfonate and triethanolamine, gave a rust rating. of D in test (A) and caused rusting in test (B) after 2 days. In the forming test, the above compositions A, B and D of, the present invention were foam resistant whereas, composition X formed a heavy foam. Compositions A, B and Dot the present invention were storage'stable for over 28 'days at roomtemperature and at 5 C., whereas with compositionX, phase separation was noted after 3 days. In the threading test compositions A, B and D gave demerit ratings of 10 to 30, whereas, composition X gave ratings of -85; In the Four-Ball Test compositions A, B and D gave weld loads of 6 00 and 1000 kg. over a 5 second period, whereas, composition X gave weld loads of 200 kg.

Compositions of this invention can be'applied with excellent results to heavy duty, high speed cutting operations where cooling and lubrication of the, tool and work piece under adverse conditions are encountered. Metals'machined with the aid offluids of this invention have excellent surface finish and are free rust and stains.

We claim as our, invention:

1. An aqueous metal working lubricant comprising a major amount of water and from about 0.5% to about 15% by weight of each of (1) water-soluble dialkali metal saltof chloro C alkyl phosphonic acid, (2) an alkanolamine salt of 210 unsaturated fatty acid, (3) free alkanolarnineand (4.) a water-solubleheterocopolymer of a mixture of randomly distributedethylene and. propylene oxides having a molecular weight of from 250 to about 450 at F. 5 Water Balance Composition E:

Dipotassium alpha-chloroethyl phosphonate 4 Diethanolamine stearate 0.1 Diethanolamine 2' Heterocopolymer of ethylene oxide-1,2-propylene oxide (72/25) having a viscosity of 450 at 100 F. 10 Water Balance Composition 'F: i V

Dilitnium chloromethyl phosphonate 3 Triethanolamine oleate 0.1 Triethanolamine 1.5 Heterocopolymer of ethylene oxide-1,2-propylene oxide (72/25) having a viscosity of 1400 at 100 F. 3.0 Water Balance Composition G: Y

' "Sodium alpha-chloropropyl phosphonate 4 Triethanolamine ricinoleate 0.5 Triethanolamine 2 Heterocopolymer of ethylene oxide-1,2-propylene oxide (72/25) having a viscosity of i 450 at 100 F. 5 Water Balance 2. An aqueous metal Working lubricant comprising a major amount of water and from about 2% to about 10% by weight each of (1) a water-soluble dialkali metal salt of chloromethyl phosphonic acid, (2) an ethanolamine salt of fatty acid selected from the group consisting of saturated or unsaturated fatty acids having from 12 to 18 carbon atoms, (3) ethanolamine, and (4) a water-soluble heterocopolymer of a mixture of randomly distributed ethylene and propylene oxides having a molecular weight of from 250 to about 1500.

3. An aqueous metal Working lubricant comprising a major amount of Water containing from about 2% to about each of dipotassium chloromethyl phosphonate, trietlranolamine oleate, triethanolamine and a water miscible heterocopolymer of ethylene oxide and propylene oxide in the mol ratio of from 75:25 to 10:90, respectively, having the molecular weight of from about 250 to about 1500.

4. An aqueous metal working lubricant comprising a major amount of water containing from about 10% each of disodium chloromethyl phosphonate, triethanolamine oleate, triethanolamine and a water miscible heteroco- 'polymer of ethylene oxide and propylene oxide in the mol ratio of from 75 :25 to 10:90, respectively, having a molecular weight of from about 250 to about 1500.

5. An aqueous metal worxing lubricant comprising a major amount of water containing from about 2% to about 10% each of dilithium chloromethyl phosphonate, triethanolamine oleate, triethanolamine and a Water miscible heterocopolymer of ethylene oxide and propylene oxide in the mol ratio of from 75 :25 to 10:90, respectively, having a molecular weight of from about 250 to about 1500.

6. A water base metal working lubricant comprising about 3% to 8% dipotassium chlorornethyl phosphonate', about 0.5% to 1% of triethanolamine oleate, from about 2 to 4% triethanolamine and from about 2% to 10% of heterocopolymerof ethylene oxide and propylene oxide in the mol ratio of from 75:25 to 10:90, respectively, having a molecular weight of from about 250 to about 1500.

References Cited by the Examiner UNITED STATES PATENTS 2,311,306 2/43 Ritchey 25232.5 2,599,807 6/52 Bersworth 260-500 2,625,509 1/53 Lang 25234.7 2,777,819 1/57 Williams et a1 252--32.5 2,858,332 10/58 Watson et al 252-325 X 2,874,120 2/59 Watson et al. 252-32.5 2,874,184 2/59 Van Winkle et al 260500 2,922,810 1/ Toy et al 260--461.310 2,960,522 11/60 Toy et al. 260--461.310 2,981,686 4/61 Reamer 252-49.3 X

FOREIGN PATENTS 539,293 9/41 Great Britain.

DANIEL E. WYMAN, Primary Examiner.

JULIUS GREENWALD, Examiner. 

1. AN AQUEOUS METAL WORKING LUBIRCANT COMPRISING A MAJOR AMOUNT OF WATER AND FROM ABOUT 0.5% TO ABOUT 15% BY WEIGHT OF EACH OF (1) WATER-SOLUBLE DIALKALI METAL SALT OF CHLORO C1-4 ALKYL PHOSPHONIC ACID, (2) AN ALKANOLAMINE SALT OF A C12-20 UNSATURATED FATTY ACID, (3) FREE ALKANOLAMINE AND (4) A WATER-SOLUBLE HETEROCOPOLYMER OF A MIXTURE OF RANDOMLY DISTRIBUTED ETHYLENE AND PROPYLENE OXIDES HAVING A MOLECULAR WEIGHT OF FROM 250 TO ABOUT
 1500. 